Long-press or Save, then set as lock screen. The image is full-screen size with the browser-bar offset already compensated — if the lines still sit a little high or low on your lock screen, nudge with ▲▼ and re-save.
Trace the real crack on this screen with your finger, then turn it into a wallpaper that lines up with it exactly.
Tracing happens on a white screen so the crack is easy to see — the style is applied after.
You can switch styles after tracing without redrawing.
For perfect alignment, install this app: browser menu → Add to Home Screen, then open it from there.